package com.hmdp.utils;

import cn.hutool.core.lang.UUID;
import lombok.extern.slf4j.Slf4j;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;

import java.util.Collections;
import java.util.concurrent.TimeUnit;

@Slf4j
public class SimpleRedisLock implements ILock{

    private String name;
    private StringRedisTemplate stringRedisTemplate;

    public SimpleRedisLock(String name, StringRedisTemplate stringRedisTemplate) {
        this.name = name;
        this.stringRedisTemplate = stringRedisTemplate;
    }

    private static final String KEY_PREFIX = "lock:";
    private static final String ID_PREFIX = UUID.randomUUID().toString(true) + "-";

    private static final DefaultRedisScript<Long> UNLOCK_SCRIPT;

    static {
        UNLOCK_SCRIPT = new DefaultRedisScript<>();
        UNLOCK_SCRIPT.setLocation(new ClassPathResource("unlock.lua"));
        UNLOCK_SCRIPT.setResultType(Long.class);
    }
    /**
     * 尝试获取锁
     *
     * @param timeoutSec 锁持有的超时时间，过期后自动释放
     * @return true代表获取锁成功; false代表获取锁失败
     */
    @Override
    public boolean tryLock(long timeoutSec) {
        // 1. 获取线程标识
        String threadId = ID_PREFIX + Thread.currentThread().getId();
        log.info("线程标识{}",ID_PREFIX);
        // 2. 获取锁
        Boolean success = stringRedisTemplate.opsForValue()
               .setIfAbsent(KEY_PREFIX + name, threadId, timeoutSec, TimeUnit.SECONDS);
        return Boolean.TRUE.equals(success);
    }

/*    *//**
     * 释放锁1
     *//*
    @Override
    public void unlock() {
        //del删除锁
        stringRedisTemplate.delete(KEY_PREFIX + name);
    }*/


    /**
     * 释放锁2
     */
/*    @Override
    public void unlock() {
        // 1. 获取线程标识
        String threadId = ID_PREFIX + Thread.currentThread().getId();
        // 2. 获取锁中的标识
        String id = stringRedisTemplate.opsForValue().get(KEY_PREFIX + name);
        // 3. 判断标识是否一致
        if (threadId.equals(id)) {
            // 4. 一致，删除锁
            stringRedisTemplate.delete(KEY_PREFIX + name);
        }
    }*/

    /**
     * 释放锁3 调用Lua脚本
     */
    public void unlock() {
        //调用lua脚本
        Long execute = stringRedisTemplate.execute(UNLOCK_SCRIPT,
                Collections.singletonList(KEY_PREFIX + name),
                ID_PREFIX + Thread.currentThread().getId());
        log.info("execute{}",execute);
    }

}
